The euactinomycetes are a subset of a large and complex group of Gram-positive bacteria known as actinomycetes. Over the past few decades these organisms, which are abundant in soil, have generated significant commercial and scientific interest as a result of the large number of therapeutically useful compounds, particularly antibiotics, produced as secondary metabolites. The intensive search for strains able to produce new antibiotics has led to the identification of hundreds of new species.
Many of the euactinomycetes, particularly Streptomyces and the closely related Saccharopolyspora genera, have been extensively studied. Both of these genera produce a notable diversity of biologically active metabolites. Because of the commercial significance of these compounds, much is known about the genetics and physiology of these organisms.
Another representative genus of euactinomycetes, Micromonospora, has also generated commercial interest. For example, U.S. Pat. No. 5,541,181 (Ohkuma et al.) discloses a dibenzodiazepinone compound, specifically 5-farnesyl-4,7,9-trihydroxy-dibenzodiazepin-11-one (named “BU-4664L”), produced by a known euactinomycetes strain, Micromonospora sp. M990-6 (ATCC 55378). The Ohkurma et al. patent reports that BU-4664L and its chemically synthesized di- and tri-alkoxy and acyloxy derivatives possess anti-inflammatory and anti-tumor cell activities.
Although many biologically active compounds have been identified from bacteria, there remains the need to obtain novel naturally occurring compounds with enhanced properties. Current methods of obtaining such compounds include screening of natural isolates and chemical modification of existing compounds, both of which are costly and time consuming. Current screening methods are based on general biological properties of the compound, which require prior knowledge of the structure of the molecules. Methods for chemically modifying known active compounds exist, but still suffer from practical limitations as to the type of compounds obtainable.
Thus, there exists a considerable need to obtain pharmaceutically active compounds in a cost-effective manner and with high yield. The present invention solves these problems by providing a novel strain of Micromonospora capable of producing a potent new therapeutic compound, as well as reagents (e.g., polynucleotides, vectors comprising the polynucleotides and host cells comprising the vectors) and methods to generate novel compounds by de novo biosynthesis rather than by chemical synthesis.